A public cloud generally refers to a model of cloud computing that is open to data storage from a plurality of users, such as organizations or individuals. A public cloud is typically located remotely from the users and controlled by a third-party vendor. A public cloud typically is secured with at least user-based authentication measures and may also be secured by cryptography means.
In recent years, there have been highly publicized leaks of data from public clouds. This has caused concern by data storage users regarding the control of their data by the third-party vendor. Users of a public cloud may not know where the data is stored, who the data is shared with, and what security measures are employed to protect the data. Users may have particular data storage needs that a public cloud may not support. For example, a user may have a data policy that the data be stored within a national boundary as opposed to in a foreign nation. In another example, a user may not want to trust a third-party vendor with control over sensitive data.
Some users have responded to these concerns by storing data at a private cloud. A user may configure a private cloud on a system under the user's control, which allows the user to customize the private cloud to suit the user's particular data storage needs. Typically the private cloud data storage would be restricted to a particular user or a particular set of users, such as users from a particular organization or family.